In Oregon right now—literally, as in, as you read this—it is Fresh Hop Season: breweries all over the state are brewing fresh hop ales and some even have been tapped already. I love fresh hop beers and for some time now I’ve been thinking that I should try brewing my own: I have several hop vines that produce around a pound of (wet) hops each year. Normally I harvest and dry them, but this year I decided to finally brew up a fresh hop ale.
Where to start? I already had a basic recipe to work from, a simple American Pale Ale (derived from a homebrew book’s clone recipe of Sierra Nevada Pale Ale), which I decided should work well to highlight the hops. This is the all-grain version:
- 9 lbs. American 2-row malt
- 8 oz. 20L Crystal malt
- 4 oz. 40L Crystal malt
- 2 oz. Cascade hops for 60 minutes (bittering)
- 1 oz. Cascade hops for 15 minutes (aroma)
(Since I employ the batch sparge technique, my grain bill is actually 13.3 lbs. 2-row, 0.73 lbs. 20L Crystal, and 0.44 lbs. 40L Crystal. And an extract-based recipe would substitute the 2-row malt with 7 lbs. pale liquid malt extract.)
Simple enough, but it was the amount of hops that I would need which was the tricky part: every beer recipe out there uses dried hops in some form, and bases the IBUs, and thus the amount of dried hops to use, on the known alpha acid percentage of the hop. Knowing the amount of dried hops a recipe calls for is fine and good, but we need to convert that to the wet equivalent. And that really relies on two variables: the moisture content of the wet hop, and the moisture content of the dried hop.
A quick bit of research online gave me the average numbers for each: hops have a moisture content of 65 to 80% when fresh, and 8 to 12% when dried. So to simplify my subsequent back of the envelope calculations, I figured the hops would start at 80% for just-picked and would be 10% if dried.
For 1 ounce of dried hops with 10% moisture content, that means 90% or 0.9 ounces of the hop is the important part: the vegetable portion that has the various compounds that make the hop, er, hoppy. To get the equivalent in fresh hops to 1 ounce of dried hops, you calculate for the ratio of important hop material to total hop weight if the moisture content is 80%—or in other words, if 0.9 ounces is 20% of the overall hop when fresh, that means multiplying by five will get you the total weight: in this case, 4.5 ounces.
So based on these rough calculations, 1 ounce of dried hops is equivalent to 4.5 ounces of wet just-picked hops. And for my recipe above, I would need 9 ounces then 4.5 ounces for the hop additions.
The only other problem I have is that I don’t know exactly what kind of hops I have growing. I suspect Cascade (that’s the obvious, likely answer especially here in Oregon) but I’ve just taken to calling them my “heirloom” hops. And without knowing the variety, guessing the alpha acid percentage (the important factor in determining IBUs and thus how bitter the beer is likely to be) is just a shot in the dark.
On brew day I had everything ready to go and after mashing in, it was time to pick the hops.
The end yield: only 11 ounces—not quite the 13.5 ounces I was shooting for, but no matter: I figured I could hedge a bit since I don’t really know the variety and my assumptions about the moisture content could be off (for instance, they might only be 70% moisture). So instead of 9 ounces, I used 8 ounces for bittering (or 4 ounces to 1 ounce of dried) and the last 3 ounces (plus a pinch of dried hops for good measure) for aroma.
I used Wyeast 1332, Northwest Ale, for the yeast, and the rest is fairly straightforward. I have five gallons of a fresh hop pale ale fermenting in the primary, five days after brewing (brew day was on Labor Day), and there is still activity in the ferment. Which I take to be a good sign.
This is, of course, a beer that needs to be drank while very fresh, as all fresh hop beers should be. If all goes well that should be in about three weeks from now, and I’ll report on the results when I crack open the first few bottles.
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